The Wuhan Coronaviruses

The Wuhan Coronaviruses were first identified in the 1960s, but we don't know where they come from. They get their name from their crown-like shape. Sometimes, but not often, a coronavirus can infect both animals and humans.  In humans, the virus causes respiratory infections which are typically mild, but may rarely be lethal. In cows and pigs they may cause diarrhea, while in chickens it can cause an upper respiratory disease. There are no vaccines or antiviral drugs that are approved for prevention or treatment.

Most coronaviruses spread the same way other cold-causing viruses do: through infected people coughing and sneezing, by touching an infected person's hands or face, or by touching things such as doorknobs that infected people have touched.

Almost everyone gets a coronavirus infection at least once in their life, most likely as a young child. In the United States, coronaviruses are more common in the fall and winter, but anyone can come down with a coronavirus infection at any time.

Coronavirus is most likely transmitted through coughing and sneezing, as is the case with influenza and other respiratory viruses, Dr. Vaishampayan said.

Scientists are scrambling to understand how easily the virus is transmitted. A close examination of one family, published on Friday in the medical journal The Lancet, suggested that the virus was passed from one ill relative to six others; only two had contact with initial patient.

The Chinese Center for Disease Control and Prevention analyzed 198 confirmed cases in Wuhan. Researchers found that 22 percent had direct exposure to the meat market, and 32 percent had contact with people who had a fever or respiratory disease.

But roughly half had neither been to the market nor had contact with anyone who was sick. Sixteen health care workers were infected while caring for patients, the report said.

The main treatment is supportive care, including making sure the patient is getting enough oxygen, and using a ventilator to push air into the lungs if necessary, Dr. Vaishampayan said. Patients should rest and drink plenty of fluids “while the immune system does its jobs and heals itself,” she said.

No drugs have been approved for any coronavirus diseases, including the Wuhan coronavirus, though an antiviral medication called remdesivir appears to be effective in animals.